Power supply, potential groups
Power supply for the Bus Coupler
The Bus Couplers require a 24 VDC supply for their operation. The connection is made by means of the upper spring-loaded terminals labelled 24 V and 0 V. The supply voltage feeds the Bus Coupler electronics and, over the K-Bus/E-Bus, the Bus Terminals. The power supply for the Bus Coupler electronics and that of the K-Bus/E-Bus are electrically separated from the potential of the field level.
Power supply for the power contacts
The bottom six connections with spring-loaded terminals can be used to feed the supply for the peripherals. The spring-loaded terminals are joined in pairs to a power contact. The feed for the power contacts has no connection to the voltage supply for the Bus Coupler. The design of the feed permits voltages of up to 24 V. The assignment in pairs and the electrical connection between feed terminal contacts allows the connection wires to be looped through to various terminal points. The current drawn from the power contacts must not exceed 10 A for long periods. The current carrying capacity between two spring-loaded terminals is identical to that of the connecting wires.
Power contacts
On the right hand face of the Bus Coupler there are three spring contacts for the power contact connections. The spring contacts are hidden in slots so that they cannot be accidentally touched. By attaching a Bus Terminal the blade contacts on the left hand side of the Bus Terminal are connected to the spring contacts. The tongue and groove guides on the top and bottom of the Bus Coupler and of the Bus Terminals guarantees that the power contacts mate securely.
Configuration interface (not for BK1250, EK1x00)
The standard Bus Couplers have an RS232 interface at the bottom of the front face. The miniature connector can be joined to a PC with the aid of a connecting cable and the KS2000 configuration software. The interface permits the Bus Terminals to be configured, for example adjusting the amplification factors of the analog channels. The interface can also be used to change the assignments of the bus terminal data to the process image in the Bus Coupler. The functionality of the configuration interface can also be reached via the fieldbus using string communication facility.
Electrical isolation
The bus couplers operate by means of three independent potential groups. The supply voltage feeds the K-Bus/E-Bus electronics in the Bus Coupler and the K-Bus/E-Bus itself in an electrically isolated manner. The supply voltage is also used to generate the operating voltage for the fieldbus.
Note: All Bus Terminals are electrically isolated from the K-Bus/E-bus. The K-Bus/E-bus is therefore completely electrically isolated.
